The Attestatie de vita is a document that you can use outside the Netherlands to prove that you are alive. Some organizations, such as a pension fund, may request you to produce this document. In the Netherlands you can use the document Bewijs van in leven zijn (Proof of being alive) for the same purpose.
The Attestation de vita is a document in French and Dutch for international use.
Do you need to use such a proof in the Netherlands? Then you need to apply for the document Bewijs van in leven zijn (Proof of being alive).
You can request both documents from your municipality of residence.